4-vinylpyridine Research Articles

Experimental and computational analysis of poly(4-vinyl pyridine) and polyvinylpyrrolidone as effective corrosion inhibitors for low carbon steel in sulfuric acid

This study investigates the inhibitory effects of poly(4-vinyl pyridine) (P4VP) and polyvinylpyrrolidone (PVP) on the corrosion of low carbon steel (LCSt) in 1 M H2SO4. Protection efficacy (%PE) was measured using mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Results showed %PE values increased with higher polymer concentration and lower temperature. At 450 mg/L, %PE reached 93.13% and 94.19% for P4VP and PVP, respectively. These polymers function as mixed inhibitors, adsorbing onto the LCSt surface per Langmuir’s model as a mode of physical adsorption. EIS indicated that higher polymer concentration increased charge transfer resistance and decreased effective double-layer capacitance. Both P4VP and PVP also reduced pitting corrosion in chloride-containing solutions. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) optimized the molecular structures of the inhibitors, evaluating electronic parameters such as frontier molecular orbital (FMO) energies, energy gap, softness, hardness, electron transfer fraction, dipole moment, and hyperpolarizability ( β ° ). Monte Carlo (MC) and molecular dynamics (MD) simulations provided insights into adsorption mechanisms, corroborating experimental findings and highlighting the effect of protonation. This comprehensive study enhances our understanding of the relationship between molecular structure and function in polymer inhibitors, improving their application in corrosion protection.

Dilatational rheological studies on the surface micelles of Poly(styrene)-[formula omitted]-Poly(4-vinyl pyridine) block copolymer at the air-water interface

A thin film of an amphiphilic block copolymer, poly(styrene)-b-poly(4-vinyl pyridine), is investigated at the air–water interface. The surface pressure - area per molecule isotherm and the static compressional modulus provide evidence of two phases, assigned as L1 and L2, respectively. The surface topography and the phase images of these phases obtained using atomic force microscope reveal the presence of surface micelles of different sizes and densities. The dilatational rheology of these phases was investigated using the oscillatory barrier method for different strain amplitudes (1−5%) and qualitatively assessed using Lissajous–Bowditch curves. It points out the emergence of nonlinearity (asymmetric shape and distorted ellipse) with an increase in strain amplitude. Using a fast Fourier transform, the amplitudes and the phases of different harmonics of the stress–strain curves were extracted, and the total harmonic distortion was determined. In contrast to L1 phase, the total harmonic distortion for the L2 phase increases monotonically with strain amplitude. Fixing the strain amplitude at 1% (small amplitude regime), the temperature as well as frequency dependence studies of the dilatational moduli were carried out. The dynamic storage moduli of the L1 phase is found to be insensitive to temperature while it decreases for the L2 phase suggesting softening. Further, evidence for solid-like viscoelastic response emerges (explained using the Kelvin–Voigt model) for the L1 phase, whereas the L2 phase show a cross-over behaviour.

Multilevel Hollow-Structured Particles through Halogen-Bond Regulated Polymer Assembly under 3DConfinement.

Engineering of hollow particles with tunable internal structures often requires complicated processes and/or invasive cleavage. Halogen-bond driven 3D confined-assembly of block copolymers has shed light on the engineering of polymer organization along with the fabricating of unique nanostructures. Herein, a family of multilevel hollow-structured particles (e.g., fully porous, multi-chamber, multi-shell, and concentric multi-layer architectures) is reported via halogen-bond regulated 3Dconfined-assembly of amphiphilic polymer networks. To do so, polystyrene-b-poly(2-vinyl pyridine)-b-poly(ethylene oxide) (PS-b-P2VP-b-PEO) amphiphilic triblock copolymer is selected, where P2VP blocks act as halogen acceptor. Meanwhile, poly(3-(2,3,5,6-tetrafluoro-4-iodophenoxy) propyl acrylate) (PTFIPA) is employed as halogen donor. Halogen-bond driven donor-acceptor linking between PTFIPA and P2VP block presented in PS-b-P2VP-b-PEO, can lead to the formation of supramolecular polymeric networks, along with the increased P2VP domain and tunable hydrophobic volume. Therefore, an adjustable packing parameter (p) is thus anticipated, which can enable the morphology transformation sequence until an equilibrium state is reached. Moreover, computer simulations are further utilized as the tool to interpret such morphologies transition and identify the precise distribution of each component. Benefiting from the tunable hollow structure and a substantial surface for transporting purpose, these structurally novel particles open perspectives toward promising applications including encapsulation, nanoreactor, and catalyst support.

Design and mediated hydrogen bonding strength of Poly(styrene-alt- N–(ethyl–4–hydroxyphenyl)maleimide) copolymer to enhance miscibility with hydrogen bonded acceptor homopolymers

In this study, the monomer N–(ethyl–4–hydroxyphenyl)maleimide (TyHPMI) was synthesized from tyramine and maleic anhydride. Subsequently, free radical copolymerization was used to prepare the poly(S–alt–TyHPMI) alternating copolymer by reacting TyHPMI with styrene. We confirmed the chemical structure using Fourier transform infrared (FTIR), 1H and 13C nuclear magnetic resonance (NMR). The sequence distribution of the poly(S–alt–TyHPMI) alternating copolymer was analyzed using mass–analyzed laser desorption ionization/time–of–flight (MALDI–TOF) mass spectrometry. Differential scanning calorimetry (DSC) measurements showed a single glass transition temperature (Tg) across various weight fractions of binary blended systems containing strong hydrogen–bonded acceptors, such as poly(S–alt–TyHPMI)/poly(4–vinyl pyridine) (P4VP) and poly(vinyl pyrrolidone) PVP, implying full miscibility. The Tg values predicted by kwei equation for the poly(S–alt–TyHPMI)/P4VP and poly(S–alt–TyHPMI)/PVP blends show a positive deviation from linearity. This deviation is due to the short alkyl chain reinforcing the addition of acidic TyHPMI units, which enhances intermolecular hydrogen bonding between the pyridyl or C=O groups and the OH units of the TyHPMI segment. As a result, FTIR spectral analyses indicate that the intermolecular hydrogen bonding between pyridyl and C=O groups is stronger in the poly(S–alt–TyHPMI) copolymer compared to the poly(S–alt–HPMI) copolymer. This is supported by the larger ratio of the inter/self-association equilibrium constant (KA/KB) value.

Rational Designing Microenvironment of Gas-Diffusion Electrodes via Microgel-Augmented CO2 Availability for High-Rate and Selective CO2 Electroreduction to Ethylene.

Efficient electrochemical CO2 reduction reaction (CO2RR) requires advanced gas-diffusion electrodes (GDEs) with tunned microenvironment to overcome low CO2 availability in the vicinity of catalyst layer. Herein, for the first time, pyridine-containing microgels-augmented CO2 availability is presented in Cu2O-based GDE for high-rate CO2 reduction to ethylene, owing to the presence of CO2-phil microgels with amine moieties. Microgels as three-dimensional polymer networks act as CO2 micro-reservoirs to engineer the GDE microenvironment and boost local CO2 availability. The superior ethylene production performance of the GDE modified by 4-vinyl pyridine microgels, as compared with the GDE with diethylaminoethyl methacrylate microgels, indicates the bifunctional effect of pyridine-based microgels to enhance CO2 availability, and electrocatalytic CO2 reduction. While the Faradaic efficiency (FE) of ethylene without microgels was capped at 43% at 300mAcm-2, GDE with the pyridine microgels showed 56% FE of ethylene at 700mAcm-2. A similar trend was observed in zero-gap design, and GDEs showed 58% FE of ethylene at -4.0 cell voltage (>350mAcm-2 current density), resulting in over 2-fold improvement in ethylene production. This study showcases the use of CO2-phil microgels for a higher rate of CO2RR-to-C2+, opening an avenue for several other microgels for more selective and efficient CO2 electrolysis.

Individual cell modification with cell surface specific atom transfer radical polymerization for enhanced Cr(VI) removal

Modifying cells with polymers on the surface can enable them to gain or enhance function with various applications, wherein the atom transfer radical polymerization (ATRP) has garnered significant potential due to its biocompatibility. However, specifically initiating ATRP from the cell surface for in-situ modification remains challenging. This study established a bacterial surface-initiated ATRP method and further applied it for enhanced Cr(VI) removal. The cell surface specificity was facilely achieved by cell surface labelling with azide substrates, following alkynyl ATRP initiator specifically anchoring with azide-alkyne click chemistry. Then, the ATRP polymerization was initiated from the cell surface, and different polymers were successfully applied to in-situ modification. Further analysis revealed that the modification of Shewanella oneidensis with poly (4-vinyl pyridine) and sodium polymethacrylate improved the heavy metal tolerance and enhanced the Cr(VI) removal rate of 2.6 times from 0.088h-1 to 0.314h-1. This work provided a novel idea for bacterial surface modification and would extend the application of ATRP in bioremediation.

Poly(vinyl pyridine) coatings cross-linked with transition metal complexes as active layers for biosensors sensitive to protein adsorption and cell adhesion

The possibility of application of poly(4-vinyl pyridine) layers cross-linked with transition metal complexes as active layers in biomedical sensors was tested. The successful modification of the P4VP coating with CuBr2 or ZnBr2 was verified using time of flight - secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The topography and wettability of the coatings were examined by using atomic force microscopy and water contact angles measurements, respectively. Tests of biological activity of coatings indicated strong protein adsorption, good biocompatibility, and no antimicrobial activity. The potential of the coatings to be used as active layers of biosensors was verified, by systematic impedance-based measurements, which showed the sensitivity of the P4VP:CuBr2 coatings to the presence of proteins and cells in different concentrations. The high selectivity of the coatings toward the defined analyte was confirmed by the specific antigen–antibody immunoreaction, and the possibility of in situ monitoring of protein adsorption and cell adhesion also for individual cells was presented. Finally, the conductive response of a bilayer system that mimics Organic Field Effect Transistor was shown. These results point to a great potential for both coatings to serve as active layers of sensitive and highly selective biosensors.

Oligoelectrolyte-mediated, pH-triggered release of hydrophobic drugs from non-responsive micelles: Influence of oligo(2-vinyl pyridine)-loading on drug-loading, release and cytotoxicity

pH-responsive polymeric micelles have been extensively studied for nanomedicine and take advantage of pH differentials in tissues for the delivery of large doses of cytotoxic drugs at specific target sites. Despite significant advances in this area, there is a lack of versatile and adaptable strategies to render micelles pH-responsive that could be widely applied to different payloads and applications. To address this deficiency, we introduce the concept of oligoelectrolyte-mediated, pH-triggered release of hydrophobic drugs from non-responsive polymeric micelles as a highly effective approach with broad scope. Herein, we investigate the influence of the oligoelectrolyte, oligo(2-vinyl pyridine) (OVP), loading and polymer molecular weight on the pH-sensitivity, drug loading/release and cytotoxicity of poly(ethylene glycol-b-ε-caprolactone) (PEG-b-PCL) micelles using copolymers with either short or long hydrophobic blocks (PEG4PCL4 and PEG10PCL10, respectively). The micelles were characterized as a function of pH (7.4 to 3.5). Dynamic light scattering (DLS) revealed narrow particle size distributions (PSDs) for both the blank and OVP-loaded micelles at pH 7.4. While OVP encapsulation resulted in an increase in the hydrodynamic diameter (Dh) (cf. blank micelles), a decrease in the pH below 6.5 led to a decrease in the Dh consistent with the ionization and release of OVP and core collapse, which were further supported by proton nuclear magnetic resonance (1H NMR) spectroscopy and UV–visible (UV–vis) spectrophotometry. The change in zeta potential (ζ) with pH for the OVP-loaded PEG4PCL4 and PEG10PCL10 micelles was different, suggesting that the location/distribution of OVP in the micelles is influenced by the polymer molecular weight. In general, co-encapsulation of drugs (doxorubicin (DOX), gossypol (GP), paclitaxel (PX) or 7-ethyl-10-hydroxycamptothecin (SN38)) and OVP in the micelles proceeded efficiently with high encapsulation efficiency percentages (EE%). In vitro release studies revealed the rapid, pH-triggered release of drugs from OVP-loaded PEG10PCL10 micelles within hours, with higher OVP loadings providing faster and more complete release. In comparison, no triggered release was observed for the OVP-loaded PEG4PCL4 micelles, implying a strong molecular weight dependency. In metabolic assays the drug- and OVP-loaded PEG10PCL10 micelles were found to result in significant enhancement of the cytotoxicity compared to drug-loaded micelles (no OVP) or other controls. Importantly, micelles with low OVP loadings were found to be nearly as effective as those with high OVP loadings. These results provide key insights into the tunability of the oligoelectrolyte-mediated approach for the effective formulation of pH-responsive micelles and pH-triggered drug release.

Colloidal and Biological Characterization of Dual Drug-Loaded Smart Micellar Systems.

Smart polymeric micelles (PMs) are of great interest in drug delivery owing to their low critical micellar concentration and sizes. In the present study, two different pH-sensitive poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP-b-PEO) copolymer samples were used for the encapsulation of paclitaxel (PTX), ursolic acid (UA), and dual loading of PTX and UA. Based on the molecular features of copolymers, spherical PMs with sizes of around 35 nm and 140 nm were obtained by dialysis for P2VP55-b-PEO284 and P2VP274-b-PEO1406 samples, respectively. The micellar sizes increased after loading of both drugs. Moreover, drug encapsulation and loading efficiencies varied from 53 to 94% and from 3.2 to 18.7% as a function of the copolymer/drug ratio, molar mass of copolymer sample, and drug type. By FT-IR spectroscopy, it was possible to demonstrate the drug loading and the presence of some interactions between the polymer matrix and loaded drugs. In vitro viability was studied on 4T1 mammary carcinoma mouse cells as a function of time and concentration of drug-loaded PMs. UA-PMs and free PMs alone were not effective in inhibiting the tumor cell growth whereas a viability of 40% was determined for cells treated with both PTX- and PTX/UA-loaded PMs. A synergic effect was noticed for PTX/UA-loaded PMs.

Orthogonal printing of uniform nanocomposite monolayer and oriented organic semiconductor crystals for high-performance nano-crystal floating gate memory

Inkjet printing is of great interest in the preparation of optoelectronic and microelectronic devices due to its low cost, low process temperature, versatile material compatibility, and ability to precisely manufacture multi-layer devices on demand. However, interlayer solvent erosion is a typical problem that limits the printing of organic semiconductor devices with multi-layer structures. In this study, we proposed a solution to address this erosion problem by designing polystyrene-block-poly(4-vinyl pyridine)-grafted Au nanoparticles (Au@PS-b-P4VP NPs). With a colloidal ink containing the Au@PS-b-P4VP NPs, we obtained a uniform monolayer of Au nano-crystal floating gates (NCFGs) embedded in the PS-b-P4VP tunneling dielectric (TD) layer using direct-ink-writing (DIW). Significantly, PS-b-P4VP has high erosion resistance against the semiconductor ink solvent, which enables multi-layer printing. An active layer of semiconductor crystals with high crystallinity and well-orientation was obtained by DIW. Moreover, we developed a strategy to improve the quality of the TD/semiconductor interface by introducing a polystyrene intermediate layer. We show that the NCFG memory devices exhibit a low threshold voltage (<3 V), large memory window (66 V), stable endurance (>100 cycles), and long-term retention (>10 years). This study provides universal guidance for printing functional coatings and multi-layer devices.

Preparation of Poly(Butadiene–Styrene–Vinyl Pyridine)/Poly(Acrylonitrile–Butadiene) Core–Shell Nanoparticles by Intermittent Seeded Emulsion Polymerization and Their Catalytic Latex Hydrogenation

Preparation of Poly(Butadiene–Styrene–Vinyl Pyridine)/Poly(Acrylonitrile–Butadiene) Core–Shell Nanoparticles by Intermittent Seeded Emulsion Polymerization and Their Catalytic Latex Hydrogenation

A Remarkable Impact of pH on the Thermo-Responsive Properties of Alginate-Based Composite Hydrogels Incorporating P2VP-PEO Micellar Nanoparticles.

A heterograft copolymer with an alginate backbone, hetero-grafted by polymer pendant chains displaying different lower critical solution temperatures (LCSTs), combined with a pH-responsive poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP-b-PEO) diblock copolymer forming micellar nanoparticles, was investigated in aqueous media at various pHs. Due to its thermo-responsive side chains, the copolymer forms hydrogels with a thermo-induced sol-gel transition, above a critical temperature, Tgel (thermo-thickening). However, by lowering the pH of the medium in an acidic regime, a remarkable increase in the elasticity of the formulation was observed. This effect was more pronounced in low temperatures (below Tgel), suggesting secondary physical crosslinking, which induces significant changes in the hydrogel thermo-responsiveness, transforming the sol-gel transition to soft gel-strong gel. Moreover, the onset of thermo-thickening shifted to lower temperatures followed by the broadening of the transition zone, implying intermolecular interactions between the uncharged alginate backbone with the PNIPAM side chains, likely through H-bonding. The shear-thinning behavior of the soft gel in low temperatures provides injectability, which allows potential applications for 3D printing. Furthermore, the heterograft copolymer/nanoparticles composite hydrogel, encapsulating a model hydrophobic drug in the hydrophobic cores of the nanoparticles, was evaluated as a pH-responsive drug delivery system. The presented tunable drug delivery system might be useful for biomedical potential applications.

A Simple Manganese(I) Catalyst for the Efficient and Selective Hydrophosphination of Olefins with PH3, Primary, and Secondary Phosphanes.

A tridentate ligand L with a P,NH,N donor motif was synthesized in few steps from commercially available precursors. Upon reaction with [MnBr(CO)5], an octahedral 18-electron complex [Mn(CO)3(L)]Br (1) is obtained in which L adopts a facial arrangement. After deprotonation of the NH group in the cationic complex unit, a neutral Mn(I) amido complex [Mn(CO)2(L-H)] (2) is formed under loss of CO. Rearrangement of L-H leads to a trigonal bipyramidal structure in which the P and N donor centers are in trans position. Further deprotonation of 2 results in a dep-blue anionic complex fragment [Mn(CO)2(L-2H)]- (3). DFT calculations and a QTAIM analysis show that the amido complex 2 contains a Mn-N bond with partial double bond character and 3 an aromatic MnN2C2 ring. The anion [Mn(CO)2(L-2H)]- reacts with Ph2PH to give a phosphido complex, which serves as phosphide transfer reagent to activated olefins. But the catalytic activity is low. However, the neutral amido complex 2 is an excellent catalyst and with loadings as low as 0.04 mol %, turn over frequencies of >40'000 h-1 can be achieved. Furthermore, secondary and primary alkyl phosphines as well as PH3 can be added in a catalytic hydrophosphination reaction to a wide range of activated olefins such as α,β-unsaturated aldehydes, ketones, esters, and nitriles. But also, vinyl pyridine and some styrene derivatives are converted into the corresponding phosphanes.

Micelles regulated thin film nanocomposite membrane with enhanced nanofiltration performance

The desalination performance of thin film nanocomposite (TFN) membranes is significantly influenced by the nature of nanofillers and the structure of the polyamide (PA) layer. Herein, a micelles regulated interfacial polymerization (MRIP) strategy is reported for the preparation of TFN membranes with enhanced nanofiltration (NF) performance. Specially, stable and ultrafine micelles, synthesized from the poly(ethylene oxide)-b-poly(4-vinyl pyridine)-b-polystyrene (PEO-PVP-PS) triblock copolymers, were utilized as regulators in the aqueous phase during the interfacial polymerization (IP) process. TFN membranes were fabricated with varying concentrations of micelles to improve their properties and performances. The structure of the PA layer was further regulated by modulating the content of trimesoyl chloride (TMC), which significantly enhances the performance of the TFN membrane with micelles. Attributable to the homogeneously dispersed micelles and the modified PA layer, the optimized membrane denoted as TFN-2–0.3 exhibits an improved separation performance of 20.7 L m-2h−1 bar−1 and 99.3 % Na2SO4 rejection, demonstrating nearly twice the permeance and 2.7 % higher rejection than that of the original control membrane, respectively. The mechanism of this MRIP strategy was investigated through the diffusion experiments of piperazine (PIP) and interfacial tension tests. The incorporated micelles effectively lower the interfacial tension, promote the diffusion of PIP and accelerate the IP reaction, resulting in a denser and thinner PA layer. Collectively, these findings demonstrate that TFN membranes with micelles exhibit increased roughness, enhanced hydrophilicity, superior rejection to divalent salts, and better acid-base resistance, highlighting their potential applications in the design of TFN membranes.

Preparation and Characterization of Nickle-based Nanocatalyst for the Regioselective Synthesis Triazole Derivatives and Antimicrobial Study

Abstract: In this research, poly (4-vinyl pyridine)-supported nickel oxide nanoparticles (P4VP-NiO nanocatalyst) as an efficient recyclable catalyst have been prepared and used for the regioselective synthesis of triazole derivatives. The nanocatalyst we characterized by Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), thermogravimetric analysis (TGA), inductively coupled plasma (ICP), and brunauer-emmett-teller (BET) surface area analysis. The most important advantages of using poly (4-vinylpyridine)-nickel oxide nanocatalysts in these reactions are the short reaction time, cost-effectiveness, easy recycling of the catalyst, and high yield of the product. Also, the antimicrobial properties of the new triazole derivatives have been studied.

Janus bottlebrush compatibilizers.

Bottlebrush random copolymers (BRCPs), consisting of a random distribution of two homopolymer chains along a backbone, can segregate to the interface between two immiscible homopolymers. BRCPs undergo a reconfiguration, where each block segregates to one of the homopolymer phases, adopting a Janus-type structure, reducing the interfacial tension and promoting adhesion between the two homopolymers, thereby serving as a Janus bottlebrush copolymer (JBCP) compatibilizer. We synthesized a series of JBCPs by copolymerizing deuterated or hydrogenated polystyrene (DPS/PS) and poly(tert-butyl acrylate) (PtBA) macromonomers using ruthenium benzylidene-initiated ring-opening metathesis polymerization (ROMP). Subsequent acid-catalyzed hydrolysis converted the PtBA brushes to poly(acrylic acid) (PAA). The JBCPs were then placed at the interface between DPS/PS homopolymers and poly(2-vinyl pyridine) (P2VP) homopolymers, where the degree of polymerization of the backbone (NBB) and the grafting density (GD) of the JBCPs were varied. Neutron reflectivity (NR) was used to determine the interfacial width and segmental density distributions (including PS homopolymer, PS block, PAA block and P2VP homopolymer) across the polymer-polymer interface. Our findings indicate that the star-like JBCP with NBB = 6 produces the largest interfacial broadening. Increasing NBB to 100 (rod-like shape) and 250 (worm-like shape) reduced the interfacial broadening due to a decrease in the interactions between blocks and homopolymers by stretching of blocks. Decreasing the GD from 100% to 80% at NBB = 100 caused an increase the interfacial width, yet further decreasing the GD to 50% and 20% reduced the interfacial width, as 80% of GD may efficiently increase the flexibility of blocks and promote interactions between homopolymers, while maintaining relatively high number of blocks attached to one molecule. The interfacial conformation of JBCPs was further translated into compatibilization efficiency. Thin film morphology studies showed that only the lower NBB values (NBB = 6 and NBB = 24) and the 80% GD of NBB = 100 had bicontinuous morphologies, due to a sufficient binding energy that arrested phase separation, supported by mechanical testing using asymmetric double cantilever beam (ADCB) tests. These provide fundamental insights into the assembly behavior of JBCPs compatibilizers at homopolymer interfaces, opening strategies for the design of new BCP compatibilizers.

DHTPY-Cu@ZOL-Enhanced Photodynamic Therapy: A Strategic Platform for Advanced Treatment of Drug-Resistant Bacterial Wound Infections.

This research was to innovate a nanozyme-based therapeutic strategy that combines aggregation-induced emission (AIE) photosensitizers with copper nanozymes. This approach is designed to address the hypoxic conditions often found in bacterial infections and aims to boost the effectiveness of photodynamic therapy (PDT) by ensuring sufficient oxygen supply for reactive oxygen species (ROS) generation. Our approach involved the synthesis of dihydroxyl triphenyl vinyl pyridine (DHTPY)-Cu@zoledronic acid (ZOL) nanozyme particles. We initially synthesized DHTPY and then combined it with copper nanozymes to form the DHTPY-Cu@ZOL composite. The nanozyme's size, morphology, and chemical properties were characterized using various techniques, including dynamic light scattering, transmission electron microscopy, and X-ray photoelectron spectroscopy. We conducted a series of in vitro and in vivo tests to evaluate the photodynamic, antibacterial, and wound-healing properties of the DHTPY-Cu@ZOL nanozymes, including their oxygen-generation capacity, ROS production, and antibacterial efficacy against methicillin-resistant Staphylococcus aureus (MRSA). The DHTPY-Cu@ZOL exhibited proficient H2O2 scavenging and oxygen generation, crucial for enhancing PDT in oxygen-deprived infection environments. Our in vitro analysis revealed a notable antibacterial effect against MRSA, suggesting the nanozymes' potential to disrupt bacterial cell membranes. Further, in vivo studies using a diabetic rat model with MRSA-infected wounds showed that DHTPY-Cu@ZOL markedly improved wound healing and reduced bacterial presence, underscoring its efficacy as a non-antibiotic approach for chronic infections. Our study suggests that DHTPY-Cu@ZOL is a highly promising approach for combating antibiotic-resistant microbial pathogens and biofilms. The biocompatibility and stability of these nanozyme particles, coupled with their improved PDT efficacy position them as a promising candidate for clinical applications.

Synthesis of iron oxide nanoparticles encapsulated poly(styrene‐co‐4‐vinyl pyridine) nanocomposites for column adsorption and photocatalytic degradation of para nitrophenol from water

AbstractStyrene (St), 1,4 vinyl pyridine (4VP) monomers and divinyl benzene (DVB) monomer‐cum‐crosslinker at different molar ratios were subjected to emulsion polymerization in the presence of FeCl2, 6H2O/FeCl3⋅4H2O followed by the treatment with an aqueous ammonia solution to produce several iron oxide nanoparticles (IONs) impregnated crosslinked copolymer composites. The resulting polymer metal nanocomposites (PMNCs) were characterized by FTIR, proton and 13C NMR, UV–visible spectroscopy, XRD, XPS, DLS, magnetic properties, SEM and TEM. The PMNCs were used for batch and column adsorption and photocatalytic degradation of p‐nitrophenol (PNP) from water. The PMNC4 composite prepared with an styrene:4VP molar ratio of 5:1 (16.7 mol% 4VP), 4 wt.% DVB crosslinker and 0.025/0.05 molar ratios of Fe(II)/Fe(III) salts leads to an optimum batch equilibrium adsorption (qe, mg/g)/removal% of 496.36/99.3 PNP from aqueous PNP of concentration 100 mg/L. The same composite showed an equilibrium PNP adsorption (qe) of 114.2 mg/g polymer and a removal% of 26.8 for an inlet feed concentration (Ci, mg/L)/flow rate (Qt, mL/min)/bed height (h, mm) of 100/30/30 in a fixed bed. The PMNC4 polymer showed a photodegradation efficiency of 98% with a 1st order rate constant of 0.029 min−1 after 70 min of degradation of 100 mg/L PNP in solar light.Highlights Copolymer network of styrene, 4 vinyl pyridine and DVB were synthesized. Iron oxide nanoparticles were introduced into the network in‐situ during synthesis. The metal polymer nanocomposites (PMNCs) were characterized. Synthesis parameters were optimized with respect to batch adsorption of PNP. PMNCs showed excellent fixed bed adsorption and photocatalytic degradation of PNP.

Fabrication of a novel hydrophilic ion-imprinted polymer based on silica-modified magnetic graphene oxide as a sensitive sorbent for the fast separation of silver ions from aqueous media

This paper aimed to evaluate the co-precipitation preparation of a novel magnetic graphene oxide ion-imprinted polymer (IIP) for the recognition and separation of silver ions in aqueous solutions. The synthesis of this adsorbent was established by thermal copolymerization of 4-vinyl pyridine (4-VP) as a functional monomer, salen as a ligand, silver ions as a template ion, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, acetonitrile and chloroform as the solvents, 2,2-azobisisobutyronitrile (AIBN) as an initiator by coating on the surface of magnetic graphene oxide as a magnetic core. The prepared polymer was morphologically characterized by the use of several characterization techniques. A batch-wise adsorption investigation was carried out to determine favorable conditions for proper adsorption, likewise selectivity and reusability. The kinetics of the adsorption process was pseudo-second order and followed the Langmuir isothermal model. The maximum adsorption capacity was 77.6 ± 0.6 mg g−1 at a pH of 4. The involvement of other competing ions revealed that the adsorbent benefits from the selective property of the imprinted cavities.

Pyridinium and trifluoromethanesulfonate bifunctional poly(ionic liquid)s for highly efficient and selective adsorption of anionic dyes

The efficient and selective removal of dyes from polluted water by low cost, durable, sustainable, and reusable adsorptions remain challenges. In this study, a pyridinium and trifluoromethanesulfonate bifunctional poly(ionic liquid)s, named Py-CF3SO3-PIL was prepared by co-polymerization of 4-vinyl pyridine (4VP), divinylbenzene (DVB) and styrene (ST), followed by quaternization with 1-bromobutane and anion exchange with lithium trifluoromethanesulfonate. The resulting bifunctional Py-CF3SO3-PIL exhibited remarkable adsorption capacity (2192 mg g−1) and efficiency (within 10 min) for selective removal (>99.9%) of methyl orange (MO) from (mixed) dye solutions. The superior adsorption capacity and selectivity of Py-CF3SO3-PIL towards the removal of MO was attributed to the strong electrostatic interactions and π-π stacking interaction between the adsorbent and MO dye. Detailed kinetic studies, adsorption isotherms, and thermodynamic experiments revealed an endothermic monolayer chemical adsorption mechanism of MO on Py-CF3SO3-PIL, which is perfectly matched with the Langmuir isotherm model (R2 > 0.999). Importantly, the Py-CF3SO3-PIL could be easily collected and regenerated for multiple repeated uses, highlighting its reusability. The exceptional adsorption capacity and selectivity towards anionic dyes make Py-CF3SO3-PIL a promising candidate for dye separation applications. Our findings will contribute to the rational design of functional poly(ionic liquid)s-based adsorbents for water purification.